Storage tanks are structures used to hold a variety of liquids at atmospheric pressure. In most cases, atmospheric storage tanks are designed as vertical or horizontal cylinders with flat or conical or sloping floors and fixed or floating roofs. These storage tanks are divided into two categories: underground and surface. Surface atmospheric storage tanks are often used to store fluids such as gasoline, water, chemicals, hazardous and corrosive fluids, which are designed according to strict industrial standards.
Fixed-Roof Tank
Of currently used tank designs, the fixed-roof tank is the least expensive to construct and is generally considered the minimum acceptable equipment for storing liquids. A typical fixed-roof tank consists of a cylindrical steel shell with a cone- or dome-shaped roof that is permanently affixed to the tank shell. Storage tanks are usually fully welded and designed for both liquid and vapor tight.
External Floating Roof Tank
A typical external floating roof tank consists of an open-topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid, rising and falling with the liquid level. The floating roof is comprised of a deck, fittings, and rim seal system. Floating roof decks are constructed of welded steel plates and are of three general types: pan, pontoon, and double deck.
We supply various versions of these basic types of floating decks, which are tailored to emphasize particular features, such as full liquid contact, load-carrying capacity, roof stability, or pontoon arrangement. The liquid surface is covered by the floating deck, except in the small annular space between the deck and the shell that is covered using sealing system.
Internal Floating Roof Tank
These tanks have both, a permanent fixed roof and a floating roof inside. There are two basic types of internal floating roof tanks:
Fixed roof tanks that have been retrofitted to employ an internal floating roof are typically of the first type, while external floating roof tanks that have been converted to an internal floating roof tank typically have a self-supporting roof or a structurally supported roof.
There are various types of atmospheric storage tanks, which can be mentioned as follows: